Accounts Receivable, Related Parties, Additions

No definition available.

Name:	amr_AccountsReceivableRelatedPartiesAdditions
Namespace Prefix:	amr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Accounts Receivable, Related Parties, Payments

+ References

No definition available.

+ Details

Name:	amr_AccountsReceivableRelatedPartiesPayments
Namespace Prefix:	amr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Accumulated Costs Incurred, Due To Management Agreement

+ References

No definition available.

+ Details

Name:	amr_AccumulatedCostsIncurredDueToManagementAgreement
Namespace Prefix:	amr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number Of Additional Wells To Be Drilled

+ References

No definition available.

+ Details

Name:	amr_NumberOfAdditionalWellsToBeDrilled
Namespace Prefix:	amr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Wells, Drilled

+ References

No definition available.

+ Details

Name:	amr_NumberOfWellsDrilled
Namespace Prefix:	amr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Wells To Be Drilled In Three Tranches

+ References

No definition available.

+ Details

Name:	amr_NumberOfWellsToBeDrilledInThreeTranches
Namespace Prefix:	amr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percent Of Interest Sold

+ References

No definition available.

+ Details

Name:	amr_PercentOfInterestSold
Namespace Prefix:	amr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent Of Interest Sold, Reduced

+ References

No definition available.

+ Details

Name:	amr_PercentOfInterestSoldReduced
Namespace Prefix:	amr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent Of Internal Rate Of Return

+ References

No definition available.

+ Details

Name:	amr_PercentOfInternalRateOfReturn
Namespace Prefix:	amr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent To Committed To Fund Working Interest Share

+ References

No definition available.

+ Details

Name:	amr_PercentToCommittedToFundWorkingInterestShare
Namespace Prefix:	amr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction, Agreement Initial Term

+ References

No definition available.

+ Details

Name:	amr_RelatedPartyTransactionAgreementInitialTerm
Namespace Prefix:	amr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction, Automatic Renewal Period Unless Terminated

+ References

No definition available.

+ Details

Name:	amr_RelatedPartyTransactionAutomaticRenewalPeriodUnlessTerminated
Namespace Prefix:	amr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Related Party Transaction, Required Notice Period To Terminate Agreement

+ References

No definition available.

+ Details

Name:	amr_RelatedPartyTransactionRequiredNoticePeriodToTerminateAgreement
Namespace Prefix:	amr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Capitalized costs which include those incurred to (1) to drill and equip those exploratory wells and exploratory-type stratigraphic test wells that have found proved reserves and (2) obtain access to proved reserves and provide facilities for extracting, treating, gathering, storing the oil and gas, including the drilling and equipping of development wells and development-type stratigraphic wells and service wells.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447

+ Details

Name:	us-gaap_CapitalizedCostsWellsAndRelatedEquipmentAndFacilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(11))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_DueFromRelatedPartiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

Name:	us-gaap_DueToRelatedPartiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest income earned from interest-bearing assets owed to the entity by related party.

+ References

No definition available.

+ Details

Name:	us-gaap_InterestIncomeRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expenses related to the managing member or general partner for management of the day-to-day business functions of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_ManagementFeeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due after 1 year (or 1 business cycle).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(11))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_NotesReceivableRelatedPartiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=amr_SeniorNotesTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=amr_JointDevelopmentAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=amr_BceStackMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=amr_NorthwestGasProcessingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=amr_HighMesaServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=amr_HighMesaServicesLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=amr_LongTermNoteReceivableFromHMSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=amr_HighMesaAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=amr_DavidMcclureVpOfFacilitiesAndMidstreamMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=amr_CompensationToRelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_VicePresidentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

RELATED PARTY TRANSACTIONS (Details)			1 Months Ended	8 Months Ended	11 Months Ended	12 Months Ended
RELATED PARTY TRANSACTIONS (Details)	Feb. 08, 2018 USD ($)	Dec. 31, 2016 USD ($)	Feb. 08, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) well	Sep. 29, 2017 USD ($)	Jan. 13, 2016 well
Related Party Transaction [Line Items]
Advances from related party					$ 9,839,000	$ 3,175,000
8% long-term note receivable
Related Party Transaction [Line Items]
Allowance for uncollectible accounts						(13,400,000)
Joint Development Agreement
Related Party Transaction [Line Items]
Number of wells to be drilled in three tranches \| well								60
Number of additional wells to be drilled \| well								20
Reduced interest (percent)		12.50%
Internal rate of return		25.00%
BCE
Related Party Transaction [Line Items]
Advances from related party					9,800,000
BCE \| Joint Development Agreement
Related Party Transaction [Line Items]
Percent committed to fund		100.00%
Drilling and completion costs (maximum)		$ 3,200,000
Working interest received (percent)		80.00%
Reduced interest (percent)		20.00%
Internal rate of return		15.00%
Advances from related party						$ 39,500,000
Number of wells drilled \| well						61
NWGP
Related Party Transaction [Line Items]
Due from related parties					1,700,000	$ 1,700,000	$ 1,500,000
Stated interest rate of senior notes							8.00%
Promissory note receivable					1,700,000	1,700,000
High Mesa Services
Related Party Transaction [Line Items]
Promissory note receivable						$ 8,500,000
HMS \| 8% long-term note receivable
Related Party Transaction [Line Items]
Stated interest rate of senior notes						8.00%
Long-term note receivable					11,700,000	$ 11,700,000
Long-term note receivable from HMS \| HMS \| 8% long-term note receivable
Related Party Transaction [Line Items]
Interest income note receivable	$ 100,000				900,000
High Mesa Agreement
Related Party Transaction [Line Items]
Incremental costs incurred and have received						832,000
Payments						(1,073,000)
High Mesa Agreement \| Affiliated Entity
Related Party Transaction [Line Items]
Long-term note receivable					10,100,000	9,800,000
Allowance for uncollectible accounts					(9,000,000.0)	$ (9,800,000)
Initial term						180 days
Renewal term						180 days
Required notice period to terminate agreement						90 days
Management fee						$ 10,000
Costs incurred prior to 2018					$ 800,000
David McClure, VP of Facilities and Midstream \| Compensation \| Vice President
Related Party Transaction [Line Items]
Total compensation received			$ 29,000	$ 1,158,000		$ 769,000